Grave complications after superior oblique tenotomy or tenectomy for Brown syndrome

Superior oblique tenotomy or tenectomy was the preferred procedure for Brown syndrome for decades. Superior oblique palsy was reported as a complication, but the complex nature of this palsy and the difficulty in treating it was not emphasized. We documented cases with distressing symptoms of unilateral and bilateral superior oblique palsy after a free tenotomy or tenectomy of the superior oblique tendon for Brown syndrome.

Four cases referred for management of complex strabismus after superior oblique surgery for Brown syndrome were identified. Case histories, complications, and corresponding management are described in detail.

All cases presented with bothersome symptomatic superior oblique palsy-incomitant vertical deviation with significant torsion, diplopia worse in functional down gaze, and anomalous head postures. Although reanastomoses of the superior oblique tendon was attempted in all cases,the procedure was modestly successful in only one case. Superior oblique palsy could not be reversed. After three procedures, Case 1 was orthotropic in primary, right, and left gaze but had a small intermittent tropia in down gaze. Case 2 underwent bilateral superior oblique operations. Despite a unilateral reanastomosed superior oblique tendon, hypertropia in down and left gaze and 15 degrees chin down position persisted. Case 3 showed correction of head tilt and a negative cover test 1 week after the second operation for iatrogenic superior oblique palsy, but stability of the procedure could not be ascertained. Case 4 had a successful attempt at reanastomosis and regained control of the vertical deviation as a hyperphoria. Both anomalous head posture and torsion improved.

Superior oblique surgery for Brown syndrome may cause irreversible serious strabismus problems. Patients are left with distressing cyclovertical deviation worse in the functional position of gaze with significant torsional component that was resistant to therapy. Although adaptive mechanisms, such as an anomalous head posture, may develop, patients are left with a permanent disability that could not be reversed. One should scrupulously adhere to the indications for surgery in Brown syndrome. Preoperative assessment of superior oblique function is stressed. An alternative surgical procedure that is potentially reversible should be considered. This should include a reliable method to recover both ends of the tenotomized superior oblique tendon in case the procedure needs to be modified at a later date.